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ASPECTS of the LIFE HISTORY of Cichla Temensis (PERCIFORMES

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ASPECTS of the LIFE HISTORY of Cichla Temensis (PERCIFORMES © 2015 Paul Reiss ALL RIGHTS RESERVED ASPECTS OF THE LIFE HISTORY OF Cichla temensis (PERCIFORMES: CICHLIDAE) AND ITS RELATIONSHIP TO THE AMAZON BASIN’S FLOOD PULSE By PAUL REISS A dissertation submitted to the Graduate School-New Brunswick Rutgers, The State University of New Jersey In partial fulfillment of the requirements For the degree of Doctor of Philosophy Graduate Program in Ecology and Evolution Written under the direction of Kenneth W. Able And approved by ----------------------------------------------------- ----------------------------------------------------- ------------------------------------------------------ ------------------------------------------------------- New Brunswick, New Jersey October 2015 ABSTRACT OF THE DISSERTATION Aspects of the Life History of Cichla temensis (Perciformes: Cichlidae) and its relationship to the Amazon Basin’s flood pulse by PAUL REISS Dissertation Director: Kenneth W. Able Abstract – Cichla temensis, the largest of the Neotropical “peacock basses”, is an economically important species for both sportfishing and human consumption in the central Amazon lowlands. As an apex predator, it is also an important component of its ecosystem. Due to taxonomic questions and a dearth of definitive information about the species’ life history and relationship to its natural flood pulse habitat, there has been a lack of effective management tools and conservation policies to protect this economically and ecologically important species. The principle motivation for the work performed for, and described in, this dissertation is to clarify these topics and provide a foundation for the creation of effective future management tools. In Chapter 1, a three-part study using morphometric, reproductive and molecular data showed that variants of Cichla temensis are members of a single species whose individuals undergo a yearly color and pattern variation correlated to their specific degree of seasonal sexual maturation. Chapter 2 used geometric morphometric techniques to analyze shape changes in the variants and their relation to the deposition of fatty reserves necessary for prespawn ii gametogenesis and postspawn maintenance during a protracted fast associated with brood guarding behavior. The study showed that the behavioral and physiological characters analyzed are related to each other and to their environment’s yearly flood pulse. Chapters 1 and 2, in conjunction with prior studies and personal observation, laid a foundation that served as the basis for Chapter 3. Habitat use and spawning behavior were analyzed in relation to flood pulse conditions and grade of color and pattern variation. The temporal and spatial linkages provided by these results enabled, for the first time, a synthesis of the species’ life history with the Amazon basin’s pulsative ecology. This new body of information can help provide a foundation for future management tools and conservation policies to maximize the economic benefits provided by this species while simultaneously creating the sustainability to protect the unique ecosystem in which it plays an integral role. iii Acknowledgements I want to thank my advisor, Ken Able, for having the patience to teach an old dog new tricks. Converting a somewhat grizzled and academically uncivilized fishing guide into a legitimate scientific investigator should be a recognized resume category. His broad knowledge and boundless insight as an ichthyologist instantly showed me where my goals lay. His unwavering consistency in shaping my scientific reasoning and streamlining (at least somewhat) my writing style has allowed me to already accomplish some of those goals; particularly the conservation oriented goals that motivated my pursuit of a graduate degree in the first place. I would also like to thank Paulo Petry and Izeni Farias for igniting the motivation I needed to return to school. As an Amazon fishing guide I have enjoyed unique access to and gained priceless perspective on this normally inaccessible wilderness. My years in Amazonia have stirred a desire to play a part in protecting its future. These two scientists made me understand that if I wanted to contribute something more than lip service and unheard grumbles to my environmental aspirations, I needed to make a commitment. I had to obtain the necessary credentials to legitimize the observations I made; to begin the research that I was in a unique position to perform; and to memorialize the resulting information. Acute Angling, an Amazon sportfishing operation, funded all of the research for this dissertation. My Brazilian friends Norberto Guedes and Wellington Melo provided me with endless support in the field and helped make much of my work possible. Tomas Hrbek and Thomas Grothues provided critical scientific and technical guidance. My iv doctorate wielding children, Michael Reiss and Jenny Reiss served as mentors and academic role models. I am grateful to all of them. Finally, I am indebted to Marsha Morin and her ability to provide adult babysitting for a part-time student who is out of the country for half the year. Marsha kept me connected at Rutgers and saved my bacon more than once when deadlines rolled right by me. v Dedication I dedicate this dissertation to my future wife, Helen, whose generosity, graciousness and strength allows me to share my heart with my other great love, the Amazon. vi Table of Contents Abstract .................... ii Acknowledgments ................ iv Dedication .................... vi Table of Contents ................ vii Introduction .................... 1 Chapter 1 - Color pattern variation in Cichla temensis (Perciformes: Cichlidae): resolution based on morphological, molecular, and reproductive data ..................... 12 Chapter 2 - Geometric morphometric analysis of cyclical body shape changes in color pattern variants of Cichla temensis demonstrates reproductive energy allocation ................... 47 Chapter 3 - A periodic environment yields a cyclical life history; How Cichla temensis adapts to its flood pulse habitat ................ 79 Conclusion.................... 144 Appendix 1 ................... 150 vii 1 Introduction Cichla temensis is a large, Neotropical, predatory fish of considerable economic importance, both as a sportfish (Myatt et al., 2005; Holley et al., 2008; Thomé-Souza et al., 2014) and for human consumption (Smith, 1981; Goulding et al., 1996). Called ‘tucunaré’ in Brazil and ‘pavon’ in Spanish speaking countries, the term “peacock bass” is applied to all fifteen currently recognized species within the genus Cichla, a basal genus within the family Cichlidae (Stiassney, 1987; Farias et al., 1999; Kullander & Ferreira, 2006). The family Cichlidae has received much attention due to its rapid speciation in African rift lakes (Barlow, 2000). African cichlid radiation has been attributed in part to the high degree of variability of cichlid pharyngeal jaw configurations (Konings, 1995) enabling the rapid exploitation of multiple ecological niches within a lacustrine system. Neotropical cichlid diversification, however, is less spectacular and more likely attributable to long-term genetic changes resulting from large-scale geological vicariance (Willis, 2007). Within the family, the South American genus Cichla has posed various taxonomic challenges. Cichla was long considered to be a sister genus to the elongate predators, Crenicichla (Stiassny, 1987). However, more recently, molecular analysis indicates that Cichla is more closely aligned within a clade that includes the genus Astronotus (oscars), (Farias et al. 1999, 2000). Until 2006, taxonomists had recognized only five species, although many researchers had suggested that several additional undescribed species existed. A revision of the genus based on morphological data 2 expanded the number of accepted species to fifteen (Kullander & Ferreira, 2006). Taxonomic uncertainty still remains, however. Karyological evidence suggests that hybridization may have occurred (Brinn et al. 2004) while molecular data suggests that groupings within the genus may differ from the morphologically based species descriptions (Willis, 2007). Within the species, C. temensis itself, there have also been ongoing taxonomic questions that are addressed by this dissertation. Cichla temensis is found in lowland flood pulse rivers in the central Amazon basin and appears to be restricted to tannin stained, acidic, blackwater systems (Winemiller, 2001). It inhabits regions of the Amazon River basin, including the Rio Negro and Uatuma drainages as well as Venezuelan and Columbian tributaries of the Orinoco (Kullander, 2003). Additionally, an active sport fishery exists for C. temensis in blackwater tributaries of the Rio Madeira and Rio Branco (Kullander, 2006; Holley, et al., 2008; Reiss et al., 2012). Within flood pulse systems, C. temensis are subject to large variations in available habitat. They occur in both lagoon (lentic) and river (lotic) habitats. Changing water levels and conditions associated with the flood pulse affect the selection of habitat, so that at varying times in the seasonal rainy/dry cycle, primary habitat selection can swing from lentic to lotic (Jepsen et al., 1997). Cichla temensis can grow rapidly during its first year, although information from its natural flood pulse habitat is lacking. In aquaculture facilities, presumed C. temensis <50 mm were found to grow 1.0 mm per day, while fish 50-100 mm in length grew at 0.8 mm per day (Braga, 1953). A study of C. temensis reared in Texas ponds indicates
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